“Dean King’s poetry is a match for Muir’s. . . . We see through this book the immense power of language to sway, the ability for selectively chosen words to convey awe and power, resentment and raw anger, to change the minds of lawmakers and tourists alike. To effectively draw strength from Muir’s writing, as King suggests we do, we might reconsider which stories are told around the campfire.”

— The New York Times Book Review

“Like an experienced trail guide, King…takes time to linger over remarkable landscapes, recount revealing anecdotes, and take worthwhile detours into subjects ranging from Muir’s explorations outside Yosemite to his celebrated 1903 ramble there with Theodore Roosevelt. Written with polish and feeling, “Guardians of the Valley” is a rich, enjoyable excursion into a seminal period in environmental history.”

— The Wall Street Journal

“Captivating…instructive…Muir’s adventures in an almost virginal Yosemite will entrance park lovers, outdoor enthusiasts and California history buffs, the narrative swept along by Muir’s shimmering, deftly excerpted prose. Larger-than-life characters — [Teddy] Roosevelt, Ralph Waldo Emerson — make star appearances. King vividly re-creates both the San Francisco earthquake and fire and the titanic political fight that would consume both the proponents and opponents of the plan to flood the Hetch Hetchy….the book will resonate with students of environmental policy — and bring to bear on stories making California headlines every day. In our era of scarce resources, wrenching cycles of flood and drought and painful cost-benefit calculations, every argument and counterargument for flooding the valley echoes even louder.”

 —Los Angeles Times

“[King] traces Muir’s relationship with Robert Underwood Johnson, the New York editor who helped transform the rangy outdoorsman into the secular saint of American conservation. . . . Guardians of the Valley brings to life two compelling figures whose flaws are more apparent in our time than they were in theirs: a reminder that history is the final editor. It’s also a poignant portrait of an era when mere words could change the world.” 

—San Francisco Chronicle

“Writer Dean King, drawing extensively on the Muir-Johnson letters, tells the story of the work they did together and the admiration they bore for each other, crafting prose as absorbing as one of Muir’s articles in the Century.” 

—Natural History Magazine

“Dean King’s account of Muir and Johnson’s “unlikely partnership” makes for an enjoyable joint biography.”

—Nature Magazine

“A library of books has been written about John Muir, many of which mention Robert Underwood Johnson, but not many adequately describe his long collaboration with Muir. In this book, Dean King remedies that oversight…very worth reading.”

—National Parks Traveler

"This comprehensively researched and compellingly readable history offers an intimate yet sweeping portrait of an inspirational friendship that literally altered the American landscape and enshrined the modern-day conservation movement.” 

—Booklist (starred review)

"Lively . . . comprehensive . . . [King turns] up small but meaningful moments of history. . . . The author is particularly adept at recounting the complex politics surrounding frontier resources in a time when official policy was utilitarian . . . a welcome study of environmental politics in action.”

 —Kirkus

“A book for anyone in love with Yosemite, California history, and our natural world.” 

—San Francisco Chronicle, Most Anticipated Books of 2023

“King probes the transformative partnership between a writer and an editor in this sparkling history. . . . King vividly chronicles Muir’s evolution from 'self-styled hobo' to forceful activist, goaded and nurtured by the 'urbane' Johnson, andweaves in intriguing vignettes of Theodore Roosevelt, Poetry magazine founder Harriet Monroe, and others, as well as rhapsodic descriptions of the Sierra Nevada landscape. Fans of Ken Burns’s The National Parks documentary will cherish this inspired account of how an American treasure was saved.”

—Publishers Weekly

"Guardians of the Valley is propulsive, revelatory, and immensely readable. Summoning new research and fresh insights into the extraordinary character of John Muir, Dean King has written an absorbing paean to a deep friendship that rescued one of the planet’s most magical landscapes from the jaws of Mammon."

—Hampton Sides, #1 New York Times bestselling author of Blood and Thunder and In the Kingdom of Ice

"Today, John Muir is considered by many to be the spiritual leader of the American environmental movement, the father of our national parks, and one of our most revered writers on behalf of wilderness. The story of how he earned those accolades began and ended in the very same place: the exquisite granite valley in northern California whose towering trees, pewter-colored cliffs, and ethereal waterfalls captivated Muir upon his arrival in the High Sierras in the summer of 1868, and whose treasures he was still battling to protect when he went to his grave almost a full half-century later. In the long arc of Muir’s life, no place was more sacred to him than Yosemite—and in the fight to protect that space and its many wonders from the ravages of commercial loggers, rapacious tourism developers, and municipal water thieves, no alliance mattered more than his friendship with Robert Underwood Johnson, the gifted magazine editor who first helped Muir to find his voice, later goaded him to hone it to a keen edge, and eventually gave him the means to draw that sword and begin swinging it on behalf of nature. In Guardians of the Valley, Dean King has forged a flaming tribute to the perhaps greatest knight of American conservation, and to the extraordinary landscape that was his paramount source of inspiration." 

—Kevin Fedarko, author of The Emerald Mile

“Just when I thought we had heard all we could read and hear about the miraculous John Muir, this wonderful book on Muir's lifelong battle to save wild lands came into my hands. Deeply thoughtful, precisely researched, it is testimony to our ongoing obligation to protect the natural world. Muir is our inspiration and our teacher.”

—Gretel Ehrlich, author of The Solace of Open Spaces

"Flush with successful conquest, in the second half of the nineteenth century, growth-obsessed United States culture undertook the systematic pillage of the American West. Capitalists accrued gargantuan fortunes as forests fell before the industrial axe, hydraulic miners dissolved mountains, and dams stilled free-flowing rivers. In Guardians of the Valley, Dean King tells the rousing tale of how muscular outdoorsman John Muir and the bookish Robert Underwood Johnson, Muir’s editor at The Century magazine, forged a friendship that marshaled the nascent forces of conservation, created the modern environmental movement, and, against all odds, saved Yosemite from the maw of industrialization and birthed the national parks—the best idea we’ve ever had.”

—Gregory Crouch, author of The Bonanza King

“There have been many books written about John Muir, but no one has so keenly identified the transformational nature of the faithful friendship between Muir and Robert Underwood Johnson. The charming, wily, and eloquent Johnson was an Eastern aesthete and Muir a rough-hewn naturalist, daring outdoorsman, fierce conservationist, a man of science, but also a poet and philosopher, who with Johnson’s impassioned guidance became a crusading political activist. Their unlikely friendship was forged in the maelstrom of the Gilded Age and in two bitter and influential battles over places both men considered hallowed – Yosemite, a battle they won, and the remote Hetch Hetchy valley, one they lost after a long, ugly war waged in the pages of newspapers and magazines and in halls of power in San Francisco and Washington. King has written a stirring tribute to the power of an alliance that transformed environmentalism in the U.S., a psalm to the radiant beauty of Yosemite, and an homage to John Muir, whom, as King assiduously sands away the polish of legend, emerges as a visionary, a mystic, and a reluctant but surprisingly accomplished political brawler dedicated to preserving the “temples of Nature” for all Americans to cherish.”

 —James Campbell, author of The Final Frontiersman and Braving It

"Read Guardians of the Valley and get swept up in the rousing and inspiring story of John Muir. In these challenging times, this riveting book reminds us of the importance of life beyond the human, and gives us a template for the climate fight ahead in the marriage of Muir's passion and Robert Johnson's political savvy. It also puts the lie to the recent clumsy attempts to cancel Muir, who, while flawed like all of us, lived a life filled with courage, passion, humor, and love. A fascinating chronicle of the man who changed the way we think about nature."  

—David Gessner, author of All the Wild That Remains

“In Guardians of the Valley, Dean King chooses Robert Underwood Johnson as the perfect cornerstone to trace John Muir’s passion to preserve natural spaces. Much like Muir found paths among the giant sequoias, King found a path among these late nineteenth-century literary giants’ archives to trace their relationship and the early American conservation movement. King starts with their historic campfire in 1889 that prompted the preservation of Yosemite and the birth of the Sierra Club and concludes with the damming of Hetch Hetchy. He tells the story so well that the reader may think that this time the valley will be preserved.” 

—Mike Wurtz, Head of the University of the Pacific Special Collections and the John Muir Papers and editor of John Muir’s Grand Yosemite: Musings & Sketches

"Guardians of the Valley propels Dean King to the first rank of writers on nature, letting us discover as if for the first time the beauty and majesty of Yosemite. And in his equally enthralling parallel story of John Muir’s partnership with editor and power broker Robert Underwood Johnson, King demonstrates how passion and politics, in support of noble causes, can unite rather than divide a nation. In that sense, this extraordinary book is more than great history.

It just might be a blueprint for our own times."

—Charles Slack, author of Liberty's First Crisis